1. Field of the Invention
The present invention relates generally to tires and more specifically to a core assembly for a pneumatic tire to permit safely running after loss of tire pressure.
2. Description of Related Art
Numerous inventions have been devised for providing increased safety for drivers who experience flat tires. Some of the most significant advances in the art have centered around ring devices for running on flat tires. Most of the conventional devices described below provide variations on flat-run ring devices comprising at least two arcuate portions for fitting over the drop well of a conventional tire rim. A few of the references discuss ring devices having an elastomeric layer for decreasing friction between the inner surface of the tire and the device; however, none of the references describes a removable safety cover for reducing frictional contact between the ring devices and their overlying tire carcasses.
For example, U.S. Pat. No. 5,660,653, issued to Gardetto, discloses a support device for a pneumatic tire wheel for bracing the tire in a deflated or run-flat condition, comprising circular segment support members. Each member has a transverse cylindrical web and radially inward projecting flange portions. The support member segments are interconnected by linkages which provide for radially extending and retracting segments so that the support device may be mounted on a fixed or one-piece wheel having a rim portion with a diameter less than the opposed tire bead support flanges. Threaded bolts are mounted on the wheel rim and extend radially outward into engagement with a link member of each of the linkages which radially extend or retract the support segments. The segment webs are crowned to aid in centering the tire on the support device during operation, and the tire gripping surfaces may be formed on the segment webs to minimize slippage of the tire relative to the support device. A significant drawback of this invention, though, is that the gripping means provided on the web portions comprise a plurality of annular projections formed by die-punching the web portion from its inner wall surface, resulting in a configuration which may have a shearing effect on the inner tire during rotation at high speeds.
U.S. Pat. No. 5,626,696, issued to Boni et al., discusses a device for running on a flat tire, the device being formed by a split ring or by two half-rings that are connected together end to end and clamped onto the rim of a wheel. The half-rings are made of a polyamide that is reinforced with long glass fibers and have a T-shaped section with an outer peripheral surface that forms a tread when running on a flat tire. The tread of each half-ring is constituted by a layer of an elastomer on the radially outer peripheral surface of the half-ring. Potential drawbacks include that the inside surface of the tire is coated with a layer of lubricant, and, unlike the present invention, the elastomeric layer is overmolded onto the peripheral surface.
Similarly, U.S. Pat. No. 5,593,520, issued to Boni et al., discloses a ring device for running on a flat tire, comprising a one-piece split ring received inside the tire and designed to fit over at least a portion of the shape of the rim. The rim is formed with a reinforced thermoplastic resin core having an annular projecting portion, and is fitted with means for fastening together the end portions of the ring and for tightening them onto the rim. In this invention, the annular projecting portion is made from an elastomer such as polyisoprene.
U.S. Pat. No. 5,194,104, issued to Wada et al., discloses a rotating core assembly for a pneumatic tire, for fitting annularly to the outer peripheral surface of the well portion of a rim. When engaged, an outer surface of the core assembly comes into contact with an inner peripheral surface of the pneumatic tire, and an inner peripheral surface of the core assembly slides over the outer peripheral surface of the well portion of the rim. The core assembly includes a sliding portion formed of a resin material and a main body to which the sliding member is secured and which is formed of a material having a high rigidity and a low specific gravity. Accordingly, since the surface of the core assembly contacting the rim is constituted by the sliding member, the core assembly is rotated smoothly when the internal pressure of the pneumatic tire declines, and the overall weight of the core assembly is reduced.
U.S. Pat. No. 5,772,805, issued to Bobst, discloses a wheel safety rim comprising three, equally spaced, contoured pads installed around the center of the outer periphery of a conventional existing wheel rim. The pads are supported by brackets welded to the rim, and the contours of the pads form a circle when positioned correctly. The pads are flexibly moveable relative to the brackets to allow for instantaneous spin balancing during wheel rim rotation as occasioned by vehicle usage. In addition to spin balancing, the wheel safety rim functions to prevent a vehicle from riding on the wheel rim when an associated tire becomes deflated. Also included is a specialized tool for facilitating the installation of the device.
U.S. Pat. No. 4,901,779, discloses a safety tire for vehicles comprising a rim, an air-filled elastic tire concentrically fastened to the rim, and an annular support body mounted on the rim and in rotatable relation therewith to prevent premature destruction of the tire during operation.
U.S. Pat. No. 5,012,849, issued to Ko, shows an internal tire support wheel for vehicles comprising a plurality of tire support plates along both corners of the tire rim, a plurality of legs extending from the support plates, foot elements posed at ends of the legs, and fastening members for serially connecting the plates, so that upon deflation of the tire, the internal support stabilizes the vehicle and prevents the vehicle from tilting.
U.S. Pat. No. 5,141,039, issued to Tansei et al., discusses a pneumatic tire for mounting on the outer surface of the well portion of a rim. The core assembly is 40% to 70% of the height of the tire, to allow for safely running over a given distance when the internal pressure in the tire has been reduced.
U.S. Pat. No. 5,186,771, issued to Carpentier et al., discloses a ring device for running with a flat tire and having articulated sensors for a vehicle equipped with a tubeless tire mounted on a one-piece rim with a drop center.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
The device to prevent the full collapse of a pneumatic tire on vehicles and large aircraft comprises a plurality of arcuate portions for cooperatively fitting over the rim of a tire. The device prevents full collapse of a tire carcass by providing a specialized support surface for the carcass of a tire experiencing loss of air. The device may be used on all tire rims such as commonly known in the art and in conventional usage, including the tire rims of trucks, buses, or any other similar motor vehicle, as well as aircraft tires inflated with nitrogen.
Large aircraft have tires inflated with nitrogen. The purpose of this is to prevent corrosion to the wheel assembly, as there exist water particles in compressed air. The tire rims of aircraft wheels mounted near brake assemblies, (i.e., the main landing gear) have temperature fuse plugs that are filled with solder. Their purpose is to melt and deflate the tire if the temperature of the nearby brake becomes too high. The present device will prevent the collapse of the tire once the fuse plug melts and deflates the tire(usually at very low speeds). The inventive device will also act as a safeguard from the tire throwing its carcass as occurred in an accident of an Air France Concord(Super Sonic Transport) during a takeoff from the Paris, France Airport.
The present invention principally comprises three arcuate band portions releasably coupled together for mounting on the drop well of a tire rim to form a substantially continuous surface. The most striking feature of the invention is the protective safety coverings removably disposed on this continuous surface. The protective coverings are provided with frictional means for engaging the inner wall of the tire to prevent circumferential or lateral displacement of the tire carcass during rotation of the wheel. These frictional means may take the form of raised hard rubber protrusions or beads, providing a significant improvement over the prior art.
Accordingly, it is a principal object of the invention to provide a new and improved device for preventing the full collapse of a pneumatic vehicle tire upon partial deflation.
It is another object of the invention to provide a device for preventing the full collapse of a tire which allows a vehicle having a punctured tire to continue running without shearing the tread of the tire.
It is another object of the invention to provide a device for preventing the full collapse of a tire which is safe for usage.
Still another object of the invention is to provide a device for preventing the full collapse of a tire which is easy to mount and dismount.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.